Patent GB-480551-A (GB)
Title: Process for the preparation of nitro and amino derivatives and of dyestuffs desired therefrom
Filed: 1937-03-05
Abstract: Nitro compounds of the general formula <FORM:0480551/IV/1> where R is any hydrocarbon radicle and R1 and R2 are aromatic radicles, substituted or not, are manufactured by condensing a nitro-halogen compound of the general formula <FORM:0480551/IV/2> with a salt, preferably an alkali salt, of a phenolic compound, preferably in the presence of an excess of free phenol.  The corresponding amino compounds are manufactured by reducing the nitro compounds.  In examples: (1) caustic potash is heated with excess of phenol until the water formed is removed, and the product is heated with 2-benzoylamino-4-chloro-5-nitrodiphenyl ether; the product is reduced to the diphenyl ether of 2-benzoylamino-5-aminohydroquinone, which may be diazotized; (2) p-cresol is used in place of the phenol in (1), producing 2-amino-3-(41-methyl)-phenoxy - 5 - benzoylamino - 6 - phenoxy-benzene.  Samples have been furnished under Sect. 2 (5) of: (A) 2-nitro-5-acetylaminohydroquinone diphenyl ether, prepared by acetylating 2-amino 4-chlorodiphenyl ether, nitrating the product and condensing the nitro derivative with potassium phenolate in the presence of excess of phenol; (B) the corresponding amine, prepared by reduction of the nitro compound with zinc powder and glacial acetic acid; (C) and (D) 2 - acetylamino - 5 - nitro - and - 5 - amino - 1 - (41 - methyl) - phenoxy - 4 - phenoxybenzene, prepared analogously to (A) and (B) by starting from 4 - methyl - 21 - amino - 41 - chlorodiphenyl ether.  Nitro-halogen compounds of the general formula given above are obtainable by acylating the corresponding aminohalogendiphenyl ethers and nitrating the products, e.g. by the action of nitric acid, alone or in the presence of a solvent, e.g. chlorobenzene or acetic acid.  For example, 2 - benzoylamino - 4 - chloro - 5 - nitrodiphenyl ether is prepared by benzoylating 2-amino-4-chlorodiphenyl ether and treating the product with nitric acid in the presence of glacial acetic acid.  Azo dyes, forming upon the material.-Cotton is dyed by coupling on the fibre the diazo compounds of the amines described above, other than those in which R is a cyclic radicle at least partially hydrogenated, with arylamides of 2 : 3-hydroxynaphthoic or acetoacetic acid.  In an example, cotton is padded with 2 : 3-hydroxynaphthoic a -naphthylamide and a reddish violet dyeing is developed with diazotized 2 - benzoylamino - 5 - aminohydroquinone diphenyl ether.  A table gives the shades obtained by using as coupling component the anilide, m-nitranilide, 5-chloro-o-toluidide, b -naphthylamide, o- and p-anisidide, o-toluidide, p-chloro-o-anisidide and 4 : 6-dimethoxy - 5 - chloranilide of 2 : 3-hydroxynaphthoic acid, and diacetoacetyl-o-tolidine.  Specifications 17279/13 and 303,838 [both in Class 15 (ii)], are referred to.  The Specification as open to inspection under Sect. 91 comprises the manufacture of the dyestuffs in substance or on vegetable fibres in general, using any coupling components of substantive character.  It contains also additional examples describing the production of 2 - benzoylamino - 4 - o - tolyloxy - 5 - nitrodiphenyl ether, and its 21 - chloro-derivative, 21 - chloro - 2 - benzoylamino - 4 - phenoxy - 5 - nitrodiphenyl ether, 2 - benzoylamino - 4 - o - chlorophenoxy-5-nitrodiphenyl ether and its 21-chloro-derivative, and the corresponding amines.  A table gives the shades obtained by diazotizing these amines and also 2-benzoylamino - 4 - tolyloxy - 5 - aminodiphenyl ether, and coupling with the components specified above, and with b  - hydroxynaphthoylamino - 3 - chloro - 4 : 6 - dimethoxybenzene. This subject-matter does not appear in the Specification as accepted.